I have a Tiffin Allegro Bus and I have over 50 halogen 20-30 watt lamps that are constantly burning out. I saw some forum where members recommended purchasing from China using alibaba.com. https://passport.alibaba.com.
Here is where you buy direct from manufacture of almost all LED's in the world and you have lots of choices.
For instance: 12vdc-220vac(12vdc), g4,g8 etc.etc bases(g4), corn configuration(corn looks like my existing halon bulbs), dimmable or non dimmable(dimmable),what type of circuit board (I choose 1340smd), 1w,2w,3, 4w,5w....(3w is a replacement for 20-30w halogen bulb), cool white, warm white ,white color rendition,Lamp 360degrees, down ligthing reflecting(360degrees.).
Now once you make all these choices you will find pricing from $.56 each to $9.99 each and they come in quantites from 1-40 per package, and they sell on a per package basis. Then there is shipping cost (my choice was free) and shipping time from 7-45 days.
Yes lower cost LED's are available but you need to know what you are looking for.
Oh by the way I have not received them yet (ordered 5 days ago for $22.80 for 40). I don't know if they will work but they sound good and I have learned a lot about LED's.
Joe Shallbetter.